Bootstrap repository scaffolding for the agent workflow - #4

Linked issue

Closes #3

Summary

Adds the Phase 0 scaffolding from ROADMAP.md so the five-agent workflow described in the README has real artifacts to operate on.

Changes

• ROADMAP.md defining Alpha and the four phases to reach it
• Structured YAML issue forms (bug report, feature request); blank issues disabled
• Pull request template with required sections
• .github/labels.yml as the declarative label source of truth
• GUIDELINES.md — 12 numbered rules the Code Critic enforces, with severity tiers
• CONTRIBUTING.md with the full label lifecycle
• CODE_OF_CONDUCT.md backing the README enforcement policy
• docs/agents/code-critic.md — reviewer configuration, prompt, and validation procedure
• README links to the new documents

How it was tested

Documentation-only change: YAML files validated locally for syntax; issue forms and PR template will be exercised end-to-end by the Code Critic validation procedure (PR #2), which uses this branch as its base.

Checklist

• This PR addresses exactly one issue
• Tests were added or updated for the change (N/A — documentation only; validation via PR Add repo stats script #2 procedure)
• The change follows GUIDELINES.md
• No unrelated formatting or drive-by changes are included